JAE 45 Help

[Alexander King]

Interesting on the way to have the sponsons hold together .. I was simply going to cut a few blocks 1" and drill through them and then glue them into the sponsons.. glue a brass tube into each block. That should hold together pin the brass tube to the booms done. Heywhire I have a 1/8" 24" x 12" ply already for the right sponson and ride pads on the bottom of the sponsons so too me it wasn't a smart buy, but I will find a use for it.. Paul Home Depot didn't have the foam in my area either alot of house development going on with no one to buy in my area. But Home Depot has a Pink foam which is the same stuff but just not in the size I want it..

Well Gentalmen I have wood material to build now. I need a few other things .. I will start making templates this weekend for sure....

oh yeah the Glue .. Yeah! Ca is way too fast for me I like the idea I can slide stuff around till I can get where I want it . Im not in a rush to have the boat done just want a perfect build in my eyes at least....besides what's 5mins Vs 2 seconds and a whole lot of bad words when its gone wrong.

 

[Paul Traufler]

Alex, forget that 5M epoxy, that stuff will not "soak" into the foam or wood before is sets, and that is the real strength of the bond you need. Go with 20+ min epoxy, you can use hobby shop brands, but West or MAS are much better. (And cost way more also!) I like the West, pretty thin so it will soak in and is very strong. I hurts to drop nearly $100 for epoxy/pumps but it is good stuff. There is a hobby shop epoxy they call it epoxy resin, something like 30 Min set time and I THINK it is made by the same people that make Zap CA glues. It is pretty good stuff and will only set you back about $12.

If I recall my foam searching the blue and the pink are the same in affect, that color is from different brands is all. It will work, it is not the aircraft quality foam but it is WAY cheaper and pretty easy to come by.

Good luck and keep us posted as to progress, and toss in a picture or three!

 

[Heywhire]

I think paul mentioned it before but the bulkhead just forward of the engine needs to have a half moon shape to it or whatever makes it easier. I have successful made my own motor mounts from some angle aluminum and tapped the holes for the screws. I think when I do this again I will get the motor lower in the tub and will mount the motor before the base coat. The only problem I have is the side are 1/4 and the rubber mount screws give me about a thread to work with. I think I might take a forstner bit and counter sink in the sides to give the nut more bite.

 

[Alexander King]

I think paul mentioned it before but the bulkhead just forward of the engine needs to have a half moon shape to it or whatever makes it easier. I have successful made my own motor mounts from some angle aluminum and tapped the holes for the screws. I think when I do this again I will get the motor lower in the tub and will mount the motor before the base coat. The only problem I have is the side are 1/4 and the rubber mount screws give me about a thread to work with. I think I might take a forstner bit and counter sink in the sides to give the nut more bite.

Heywhire

You cant find longer Nylon screws instead of counter sinking the screws? Also not to be critical I was looking at your motor compartment and where you placed angled wood along the bottom there are a few areas where there are gaps.. you might want to fill those in to keep the wood water resistant and the hull structurally sound.One other question how far is you stuffing box from the radio box bulk head too where it reached the motor? It looks really long...

 

[Paul Traufler]

Heywhire I am with Alex on this one, the flex cable is unsupported too much. (It will "whip" and then all heck will break loose!) I know I have a slighty different motor placement but yours does look to be more forward than the plans call for. Maybe the OS motor is shorter than the AA45 I do not know on that one. With those 1/4" sides you have WAY more strength so I would say 1/16 ply bottom is perfect for this task. Yes longer bolts is the path to take, remember you need 3 full threads in the nut to get 100% of the bolt strength. (Another one of those engineering rules!) I like the half moon cut out, was thinking to do this one myself, may just do a drain hole as I could do the half moon later if it is needed.

Be careful with the bolt through the boom rods in the center of the tub, that looks like a 4-40" (or bigger) and that will cut down the material of those 5/16 CF rods pretty thin. Really a 2-56 bolt in shear (the major load in this application) is more than the sponsons can take, so guess what will break first? Keep going and you will be in the water pretty soon!

 

[Heywhire]

Paul / Alex

Look on page 2 post 25 or 26 and you will see how long the stuffing tube is unsupported. I put the glow plug of the engine on the center line and the plans called for the bulkhead placement to be there. I still have to put the flywheel and collet on the motor and was thinking it was going to leave me about 1/4 inch from collet to stuffing tube where the cable would show. I thought the flex had to be protected or in the tube as much as possible? I guess I can put in another bulkhead for support.

Yeah those hole are kinda big and maybe I should have made them small but cant go back now but I will note it for my next one. I am going to remake the engine mount and use nylon bolts.

I see that now alex about the gaps, I am going to seal all that up before it hits the water.

 

[Paul Traufler]

I understand the plans and all, I really do think your OS motor is a good bit shorter than the AA motor, and your motor placement is more forward than mine is all. I do think you have too much stuffing tube unsupported in the engine bay area, I would add a bulkhead or maybe a "wedge" under the stuffing tube something for more support. Very little movement there will tear up the stuffing tube very fast, it will not be pretty! But if all is in line and balanced then no issues. Man we are getting some good build notes here!

 

[Alexander King]

I understand the plans and all, I really do think your OS motor is a good bit shorter than the AA motor, and your motor placement is more forward than mine is all. I do think you have too much stuffing tube unsupported in the engine bay area, I would add a bulkhead or maybe a "wedge" under the stuffing tube something for more support. Very little movement there will tear up the stuffing tube very fast, it will not be pretty! But if all is in line and balanced then no issues. Man we are getting some good build notes here!

Yes build notes are important .. I was looking at the Plans last night and I saw a few things that may be too late for Heywhire to change in his hull this time around and some changes that are in yours from the photos I saw. I was going to drive down to Huntsville today but I deiced to stay close to home its raining cats and dogs here.. So I wont get a chance to see Dave Hall or anyone to get some ideas of which way to go. But looking at the drawings I found that what Heywhire has done was what the drawing calls for. There are a few things in the drawings that are intuitive to a experienced builder and not so for a first time builder I see why its important to discuss those issues here.. Paul I think on your hull that Dave started for you there are some minor changes in bulkhead arrangement. Im using a CMB 45 EVO 1 and its way shorter then a AA45 or a OS 46. and with the CMB in place where the drawing calls for the motor to be mounted there is almost a mile of unsupported stuffing box and cable. This is with the collet attached to my motor with fly wheel and figuring a 1/4 gap from the collet to the stuffing box. With that said I would like to see what Heywhires OS46 motor will look like with the fly wheel and collet in place and mounted in the hull as per drawings and then see how much stuffing box is unsupported. Paul back to your hull As I was saying your hull had some minor changes and last night while making the templates for the hull and sponsons to transfer to the wood I started to play with the locations of the bulkheads on the drawing to look more like your hull. Lets say looking from bow to transom starting with the bulkhead near the bow called #1 and the transom called #5 (remember we added a bulkhead for the bait box). I can see #1 has been moved back. I would think the main reason was you can add more flotation, you didn't need all that room for fuel or you would be able to run a race in Japan off shore no problem with that much fuel. #3 was moved forward at least 2.5" along with #4 so the radio box dimension hasn't changed from the drawing it just moved the raido box forwards. By doing this has now made the stuffing box supported pretty close to the end, coupled that with relocating the motor mount back say .25" you wont have to worry about supporting the stuffing box the motor would be closer to the support of the bulkhead (this was my educated guess using my engine (shorter power plant) to come up with the configuration that you have Paul on your hull.. mind you this is not confirmed and it was late I was tired I would like to get in touch with Dave about the changes before I start. IF not I will just use my educated guess for trial and error.. for some strange reason I think it will work out fine)

Heywhire could you take a photo of your motor with Flywheel on and collet and the motor placed in the hull close to where the drawings call for. If you could, remove the cable I would like to see if the collet touches the the stuffing box..and where.

I will pass on some advice to first time builders.. From someone who took me under their wing schooled me about building boats and outriggers. It is very important the lining up of the drive line! if there is a mm off center alignment the boat can be ruin! Whip is your enemy... When building a boat it is always good to have the motor (W/ collet) before you start the build along with the cable and stuffing box. This way you can make sure this alignment is correct. Always mount (bolt in) the engine first as per drawing or instructions, then tack the stuffing box in place that way you can adjust it to align correctly to your bolted in motor. When the cable can slide in and out of the collet free without touching it glue the stuffing box in place check and check again to make sure it is aligned properly. I just wanted to pass that on for build notes and for those who are thinking about building a rigger or any boat out there.

Well Guys enjoy your Saturday! Will come back here later on to see what is what.

 

[Paul Traufler]

Alex, worked out as David could not make it to HSV today anyway. (I'm not there also!) I would suggest you email David and ask about the plans to build differences, but other than the motor location I do not think it is criticial placement either. Wish I could be more help but I do not have measurements with me to pass on. I agree getting the motor to flex shaft lined up is VERY important, if its off bad things happen FAST!

 

[Heywhire]

Alex,

Here is a picture of the motor and stuffing tube location. I don't have a flywheel for this motor but the collet is on it. I am just building off of plans and tried to find pictures of someone who built this before but could not find. The plans do call for the motor to be on the CG of the tub so I lined up the center of the glow plug, from side to side and front to back. I did make new mounts and looked to the KEPs 21 for the idea, I took nylon bolts thru a rubber grommet with nylon washers as spacers, works pretty good. My next one will be way different, I have drawn theses plans up in cad and plan to layer the sides, like 1/16 ply then 1/8 ply with lightning holes the adding another 1/16 shaped where needed like the boom areas, engine mount area and any other place it needs beefed up support.

Also, I noticed today looking thru the picture that I forgot to put in the cooling tube from the transom to the engine bay, what a dumb ass!@#$%^ I almost gave up on it and went with the KEPS.21, these plans are drawn out awesome!

http://ne-stuff.blogspot.com/2008/12/keps-21-freebie-pdf-drawing.html

Does anybody know the thickness of the aluminum for the turnfin, I was reading on another post that the turn fin they were talking about was 1/16 or 1.6mm, I just got some sheet aluminum from home depot and 1/16 seems flimsy.

Like I said, the next one will be way different.

 

[Heywhire]

Support issue fixed........

 

[Alexander King]

Alex,

Here is a picture of the motor and stuffing tube location. I don't have a flywheel for this motor but the collet is on it. I am just building off of plans and tried to find pictures of someone who built this before but could not find. The plans do call for the motor to be on the CG of the tub so I lined up the center of the glow plug, from side to side and front to back. I did make new mounts and looked to the KEPs 21 for the idea, I took nylon bolts thru a rubber grommet with nylon washers as spacers, works pretty good. My next one will be way different, I have drawn theses plans up in cad and plan to layer the sides, like 1/16 ply then 1/8 ply with lightning holes the adding another 1/16 shaped where needed like the boom areas, engine mount area and any other place it needs beefed up support.

Also, I noticed today looking thru the picture that I forgot to put in the cooling tube from the transom to the engine bay, what a dumb ass!@#$%^ I almost gave up on it and went with the KEPS.21, these plans are drawn out awesome!

http://ne-stuff.blogspot.com/2008/12/keps-21-freebie-pdf-drawing.html

Does anybody know the thickness of the aluminum for the turnfin, I was reading on another post that the turn fin they were talking about was 1/16 or 1.6mm, I just got some sheet aluminum from home depot and 1/16 seems flimsy.

Like I said, the next one will be way different.

Yeah! don't worry about making mistake everyone does.. worry about when no one tells you whats wrong. At least you saw you didn't have a way of cooling the motor and corrected the problem. Yeah the KEP 21 is a nice boat one day Ill get to it. As for the project... so looking at your photo it looks like you have 2 3/4" that is unsupported. yeah I don't know.. Heywhire think about adding not a bulkhead but some sort of support under there for at least a 1 1/2" the length should help. that's a long stuffing box that can whip and destroy the boat in a blink of an eye.. so keep it structurally strong. PM me If you need help I work with CAD also and could give you a better visual of what might be a good idea.

Get the turn fin from the guy paul got his.. you cant go wrong with it...

 

[Paul Traufler]

Heywhire, forget that 1/16 al. from Home Depot, no way that would be strong enough. 6060 T6 3/32" thick would work fine, but as Alex said it may bebest to get one that is already made up and of the right material. These JAE will turn on a dime, and leave 2 nickles behind, so the load placed on the turn fin is pretty high. The turn fin is one of the important items to make the boat run and turn correctly. I'm with Alex on more support for the stuffing tube, perhaps a "wedge" under it with some CF or fiberglass cloth over it would work. Keep up the building!

 

[moparbarn]

turn fin strength, mounting & right sponson strength cannot be stressed enough!! eric bourlet is running a .21 size FE JAE with an eagle tree data logging system. has posted that he is seeing 7 g's in turns. that's a HUGE load on the fin, sponson & fin mounts. a .45 boat should be higher g's, due to the higher weight & speed. "do it nice, or do it twice" B) go back & read rick glover's post (page 1, post #3) about turn fin mounting in this thread.

 

[Alexander King]

turn fin strength, mounting & right sponson strength cannot be stressed enough!! eric bourlet is running a .21 size FE JAE with an eagle tree data logging system. has posted that he is seeing 7 g's in turns. that's a HUGE load on the fin, sponson & fin mounts. a .45 boat should be higher g's, due to the higher weight & speed. "do it nice, or do it twice" B) go back & read rick glover's post (page 1, post #3) about turn fin mounting in this thread.

Heywhire sorry I dont think that fix is nothing but a band aid my friend not down grading your work just that you can fix it temporary or do it right and be done with it....

I think Paul and Moparbarn are also both giving some pretty sound advice here... Pauls solution to the support for the stuffing box may be the best bet, but you're going to have to mount the motor in its new home first for alignment reasons. The next logical step would be to measure and build up a wedge almost the length and the width of the stuffing box and glass or carbon fiber in the stuffing box as Paul said. One thing, I am now thinking about where you are on this build.. Being you have installed your stuffing box, you now have to mount the motor to the angle (if there is one called for) that matches the suffing box with the flex cable installed. not the other way around like it should be done but this is a learning experience for you so. You could either take off the sky with heat and remove the stuffing box and mount the motor as per drawing and Align and properly install a new stuffing box and sleep at night knowing that the flex cable wont whip and destroy your work after maybe one run or try to mount the motor with stuffing box in place which is hard to do and take a chance. You really need to maybe bite the bullet here being your behind the 8 ball with having the stuffing box installed along with the ski and having the motor to install with a unsupported stuffing box. Again this is and learning experience for you and outriggers really call for perfect building and alignment for perfect performance.

The turnfin: Moparbarn 7 G's in a 21 size JAE FE rigger that's impressive! Yeah! a 45 with the weight alone will have to have pretty Beefy construction on the sponson to stay in one piece and the turn fin has to be made well..

there is proof Heywhire 7 g's is nothing to shake a stick at

 

[Heywhire]

Alex,

The engine is lined up according to the plans. It is at the CG of the boat and as you read earlier I was asking if the engine was tilted to the tub bottom or horizontal to the tub bottom and I got PM'ed stating to do it horizontal. The stuffing tube is centered and horizontal to the tub bottom also. I created the extra bulkhead and split the difference of what the stuffing tube was unsupported.

Also, my right sponson IS beefed up with 1/8 on the inboard and 1/8 on the outboard angle along with 3/8 dowel x3 going thru the sponson where the turn fin will be mounted and 30 minute epoxied in.

 

[Alexander King]

ok go for it !

 

[Paul Traufler]

Hey its time for another math class! Oh man the dog ate my homework...

Lets figure out the "G loading" of a boat going around a corner. Ok we will jump right into the simple formula:

Ar = V*V/r

Where:

Ar = is the acceleration (or G load) of the boat around a corner

V = the the boat velocity (if in MPH we need to change to Ft/Sec, take MPH * 1.4666 and you get Ft/Sec)

r = Radius of the corner, in IMPBA 1/3 mile oval course the R = 35 Ft

So a boat going 60 MPH and taking a very tight turn around the buoys (5 ft off of them to make a 40 ft radius corner) we would have:

V = 60MPH * 1.4666 = 88 Ft/s

Ar = (88Ft/s * 88Ft/s) / 40 Ft

Ar = 193.6 Feet per second squared (Ft/s^2)

But ae want the results in G's so here on Earth at the surface we have acc. due to gravity at 32.2 ft/s^2

Ar = 193.6 Ft/s^2 / 32.2 Ft/s^2

Ar = 6 G's

We can play with the formula above for speeds and turn radius to do many what if's, but it is plain to see the boats have a rather high load placed on them to make the corners at the speeds some of them are going. SO that 5 lb boat doing a 6 G turn would have a 30 lb load placed almost completely on the turn fin!

Just for grins, a person can not withstand 9 g's for very long (seconds) with out some ill affects!

 

[Heywhire]

Well, I am giving up on this project and going to go with the KEP's 21 where everything is cut and dry. This is too much thinking and is taking the fun out of the build. Thanks all for your advice.

 

[moparbarn]

don't be a quitter. you will NEVER learn anything or advance your skills that way. you've got the info, and have invested time & money in the .45 jae. don't give up now .............